build(deps): bump github.com/prometheus/client_golang

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.17.0 to 1.18.0.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/main/CHANGELOG.md)
- [Commits](prometheus/client_golang@v1.17.0...v1.18.0)

---
updated-dependencies:
- dependency-name: github.com/prometheus/client_golang
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

go.mod

@@ -5,7 +5,7 @@ go 1.15
 require (
 	github.com/BurntSushi/toml v1.3.2
 	github.com/alecthomas/kong v0.8.1
-	github.com/prometheus/client_golang v1.17.0
+	github.com/prometheus/client_golang v1.18.0
 	github.com/stretchr/testify v1.8.4
 	gopkg.in/yaml.v3 v3.0.1
 )